1. Field of the Invention
The invention pertains to novel photographic apparatus for use with film units of the self-developing type. More particularly the invention pertains to an apparatus with improved means for initiating exposure of such film units and for advancing the film units from the exposure position to initiate processing. The invention further provides improved means for generation of electrical energy for the purpose of, for example, providing artificial illumination for the exposure of a film unit.
2. Description of the Prior Art
Photographic apparatus of the self-developing type are generally provided with a chamber for supporting a cartridge containing a plurality of film units with a foremost one thereof located in proper position for exposure. After exposure of the foremost film unit a shuttle is actuated to advance the exposed film unit into a pressure applying means to rupture a pod of chemical activator solution incorporated within the film unit and to uniformly spread the chemical solution over the image forming areas of the film. In the past various means have been proposed for synchronizing the several camera functions such as exposure and film unit transport so that these functions are performable in only the desired sequence thereby precluding anomalous operations by those perhaps unfamiliar with the operation of the camera. In designing cameras that are relatively simple to operate, it is generally necessary that the internal mechanisms of the camera be made more complex than would otherwise be required. Interestingly, it is also desirable to have the cameras that are the simplest to operate be relatively inexpensive to be attractive to the great numbers of people who do not wish to be troubled with the operation of a complicated camera but who instead enjoy obtaining pictures of loved ones, etc. The design of a camera that is simple to operate and which may be manufactured at relatively low cost represents a substantial challenge to the camera designer.
In the prior art numerous functional designs have been proposed for self-processing cameras. For example in U.S. Pat. No. 2,873,658 there is described a self-processing camera that comprises a movable rack having feet that are adapted to engage an edge of a film unit after exposure thereof and push the film unit from its exposure position through a pair of opposed non-driven pressure rollers. The plunger-like rack is coupled to the camera's shutter so that upon initial advancement of the rack an exposure of the film unit is made. Further movement of the rack moves the film unit through the pressure rollers and results in the spreading of a developer solution on the image forming portion of the film unit. The patent indicates that the camera described therein is particularly suited for pictures of 35mm size or smaller. The camera would not be particularly well suited for use with substantially larger film formats such as the approximately 4 inches (10cm) square size known presently for instant prints since it is undesirable to push a film unit of relatively large dimension through non-driven pressure rollers. The pressure rollers are generally required to be heavily spring biased towards one another and a relatively large force would be necessary to push a large film unit between them, thereby raising the likelihood of damage to the film unit.
In another approach disclosed in U.S. Pat. No. 3,767,404, a picker device is provided which includes a film engaging portion at one end thereof for engaging a trailing edge of an exposed film unit and a rack portion at an opposite end for engaging a gear driven by a handcrank. The gear is also coupled to a pressure roller and rotation of the crank advances the picker unit from its rearwardmost position forwardly so that a film unit is eventually engaged and moved into the pressure applying means. Rotation of the crank simultaneously drives the pressure roller so that the pressure roller moves the film unit through the pressure applying means. The patent further discloses that a cam may be provided to disengage the picker from the gear and hold the picker unit in its forwardmost position out of engagement with the gear after delivery of the film unit into the pressure applying means. The picker unit remains in this latter position until released by operation of the camera's body release or shutter release whereupon a spring urges the picker unit to be moved back to its rearwardmost position after operation of the shutter. Inasmuch as actuation of the shutter occurs prior to release of the picker unit from its latched position additional mechanisms would be needed to preclude the possibility of the operator inadvertently exposing a film unit twice prior to processing of the film unit.